Ink jet printing apparatus with overrun of printhead to insure better visibility

ABSTRACT

An ink jet printing apparatus has provision for both line printing and character-by-character printing. A directionally oriented grating and associated circuitry is provided to maintain a record of character and ink drop printing locations. Also, provision is made for over-shooting the printhead some distance past each character printed during an incremental mode and for stopping the printhead to enable better visibility of the character just printed. Upon printing of the next character, the printhead first moves to the left a sufficient distance to get past the character box to be printed and sweeps to the right with the overshoot and stopping as before.

United States Patent [191 Woods et al.

[11] 3,831,728 [451 Aug. 27, 1974 INK JET PRINTING APPARATUS WITHOVERRUN OF PRINTIIEAD TO INSURE BETTER VISIBILITY Inventors: Joe W.Woods; Krikor Yosmali,

both of Lexington, Ky.

Assignee: International Business Machines Corporation, Armonk, NY.

Filed: Dec. 11, 1972 Appl. No.: 313,886

US. Cl...... 197/1 R, 346/75, 197/19, 197/66 Int. Cl. G0ld 15/18 Fieldof Search 10l/DIG. 13; 346/75, 140, 346/] R; 197/1 R, 19, 60, 62, 63-66,68;

. References Cited UNITED STATES PATENTS Stone et a1 346/75 3,595,9947/1971 Whitman 346/75 X OTHER PUBLICATIONS A. B. Dick, Videojet Printer,Techn. Description, 4 -12-71.

Primary ExaminerRobert E. Pulfrey Assistant Examiner-E. H. EickholtAttorney, Agent, or FirmD. Kendall Cooper [57] ABSTRACT An ink jetprinting apparatus has provision for both line printing andcharacter-by-character printing. A directionally oriented grating andassociated circuitry is provided to maintain a record of character andink drop printing locations. Also, provision is made for over-shootingthe printhead some distance past each character printed during anincremental mode and for stopping the printhead to enable bettervisibility of the character just printed. Upon printing of the nextcharacter, the printhead first moves to the left a sufficient distanceto get past the character box to be printed and sweeps to the right withthe overshoot and stopping as before.

3 Clairm, 8 Drawing Figures PAIENIEMI 3.831.728

sum ior 4 Pmmenwm w 3381.128

sum aor 4 v FIG. 3a

v f 1 I POWER on RESET PRINT CHARACTER K D/AI- LINES lNKJE-T 122 v HEADREADY CHARACTER smc. CLOCK GENERATOR BLM-IK/UNBLANK {56 LPROCESSORZMAGNEHC NEXT END OF CHARACTER I CARD UNIT {25 /i57 PRINT i59b-CHARACTER LINES 26 A58 CLOCK CLOCK R 1590 NUMERIC PRINTER Q I i 1 STARTOF. SCAN NEXT CLOCK v 128 fF-lG.3b

1 50 1e0 461 CHARACTER LINES I FEEDBACK PR'NT i' g f g MECHANICALMAGNETS, PRINTER READY 3 FUNCTIONS SPECIAL MECHANICS 154 LOGIC cmcunsPRINT v conPARE 1 3 or CHARACTER T I 156 DOWN COUNT LOGIC AMPLIFIERAMPLIFIER RELATED PATENT APPLICATION US. Patent application Ser. No.313,919 entitled, Ink Jet Printing Apparatus with Line Sweep andIncremental Printing Facilities, filed Dec. 1 l, 1972 and having RaymondL. Fowler, et al, as inventors.

BACKGROUND OF THE INVENTION AND PRIOR ART The Rossetto patent describesphotocomposing apparatus making use of a grating for determination ofcharacter increments. The Stabler patent describes a shaft positionindicator for recognizing direction of rotation of a shaft and having anassociated counting means. The Woodhead patent describes a counter forkeeping track of printer position.

The Sims patent describes a power typing system incorporating an IBMSelectric printer with an associated magnetic tape storage unitwithrecording and reading facilities; Line readjustment capabilities are"also described. The Locklar, et a1, patent describes an apparatussimilar to the Sims system with provision for selection of informationon a character, word, and line basis. The Jones, et al, patent describesan automatic typing system incorporating an IBM Selectric" Typewritertogether with an associated magnetic card storage unit having recordingand reading facilities. The Hayes patent describes an electricalkeyboard unit.

The Burdick, et al, and Dorius, et al, publications described ReedSwitch Assemblies.

The various IBM Customer Engineering Manuals describe the Selectricprinter,,the Selectric" Model 11 printer, and the Selectric" printer andmagnetic card unit in the IBM MC/ST.

REFERENCES or INTEREST The following U.S. Pat. Nos. are of generalinterest: Rossetto, et al, Reissue 25,354; Stabler, 2,656,106; Woodhead,2,954,860; Sims, 3,297,124; Locklar, et al, 3,260,340; Jones, et al,3,512,137; Hayes, et al, 3,494,550. j

The following IBM publications are of interest:

"Reed Switch Contact Block,authors, R. L. Burdick, et al, IBM TechnicalDisclosure Bulletin, October 1966, page 512.

Toggle and Momentary Reed Console Switch Assembly, authors, L. F.Dorius, et al, IBM Technical Disclosure Bulletin, May 1967, pages 1,702and 1703.

The following IBM Customer Engineering Manuals are of interest:

Selectric" Printer Instruction Manual, January, 1966, Form No. 241-5032.

Selectric" Typewriter, Service Manual, November, 1970, Form No.241-5615. I

Selectricll Typewriter, Service Manual Supplement, Form No. 241-5615(Supplement).

Magnetic Card Selectric Typewriter, Self Teach Course Summary, July,1969, Form No. 241-5581.

Magnetic Card Selectric Typewriter, Self Teach Instruction Manual, Vol.11, June, 1969, Form No. 241-5580.

Parts Catalog, Magnetic Card Selectric Typewriter, August, 1969, FormNo. 241-5584.

Pictorial Reference/Adjustment Manual, Magnetic Card SelectricTypewriter, July, 1969, Form No. 241-5593.

SUMMARY OF THE INVENTION The present ink jet printing system hasprovision for both line printing and incremental printing withstructures involving considerably less hardware than some other printingapparatus. As an example, with the present system, the escapement rack,backspace rack, escapement and tab bracket assembly, escapementtriggering device and associated hardware including the tab torque baris eliminated. The carrier motion is accomplished by actuationof'carrier return and tab solenoids in correct'timeintervals. A singlecharacter is printed under control of the electronics which senses agrating for positioning of the character to be printed. The grating hastwo sets of markings displaced from one another and an associatedcounter circuit keeps track of carrier location in relation to adocument to be printed by counting up and down as appropriate.

Provision is made to insure improved visibility of the printing lineduring printing operations, particularly when printing is performed on acharacter-bycharacter basis.

OBJ ECTS Accordingly, a paramount object of the present invention is toprovide an ink jet printing apparatus having line and incrementalprinting capabilities.

Another object of the present invention is to provide adirectionallyvoriented grating and associated counting circuitry formaintaining character and drop locations during printing operations.

A further object of the present invention is to establish improvedvisibility of the printing line during printing operations.

The foregoing and other objects, features, and advantages of theinvention will be apparent from the following more particulardescription of the preferred embodiment of the invention as illustratedin the accompanying drawings.

DRAWINGS In the Drawings:

FIG. 1 illustrates an ink jet printing system incorporating a printerand having an associated magnetic card recording/reproducing unit withboth line printing and character-by-character printing facilities.

, FIG. 2 illustrates various carrier motions encountered duringincremental printing.

FIG. 3a is a block diagram of the ink jet printing apparatus of FIG. 1showing a number of significant control lines and possible data sources.FIG. 3b is a block diagram illustrating some of the printer mechanicalsignals involved.

FIG. 4 illustrates structures in the ink jet printer head assembly withassociated grating.

FIG. 5a illustrates a sensor assembly useful with the grating shown inFIG. 4, while FIG. 5b illustrates a sensing circuit fulfilling anamplifier function.

FIG. 6 illustrates various mechanisms involved in producing relativemotion of the ink jet head assembly and carrier in relation to adocument to be printed.

DETAILED DESCRIPTION FIG. 1 illustrates an ink jet printing systemincorporating a typewriter 1 with an associated magnetic cardrecording/reproducing unit 2. Card unit 2 is shown for convenience onlysince by inspection of FIG. 4a, it is apparent that other kinds ofstorage units, recording- /reproducing units, and the like, may be usedin the system. Typewriter 1 has the usual keyboard 2 which preferably isof the electrical type referred to in some of the IBM CustomerEngineering Manuals listed previously. It may also be of the typedescribed in the Hayes. et al, patent. Printer 1 incorporates an ink jethead assembly 4 arranged for travelling movement from left to right (andconversely) adjacent a document 7 to be printed. Assembly 4 has an inkdrop nozzle and an associated gratingS with an upper incremental columnlocation scale and a lower character scale as shown in greater detail inFIG. 4. Printer 1 may be provided with various control buttons 10, 11,12 and 13 for automatic, line, word, and character printing,respectively. Other keybuttons 15-18 concern mode selection, that is,record, playback, adjust, and skip, respectively.

Reference is made to the various Selectric" typewriter manuals referredto previously for description of other keyboard facilities and otherfeatures of the printer. The magnetic card unit 2 has a load slot 25 anda track indicator 26. Also provided on unit 2 is a card eject button 27,a track stepdown button 28 and a track stepup button 29 for relocatingthe scanning transducer with respect to the various tracks on the card.Reference is made to the various magnetic card manuals and the Jones, etal, patent for a description of facilities in the card unit. It isunderstood, of course, that other kinds of storage facilities, cardunits, tape units, processors, and the like can be substituted for unit2 including as an example, the magnetic tape unit set forth in the Simsand Locklar, et al, patents.

Printer 1 incorporates a left margin reed switch 30, a drop carrierreturn reed switch 31 and a right margin reed switch 32. These may be ofthe type set forth in the Burdick. et al, and Dorius, et al,publications.

FIG. 2 illustrates the mechanical motion of the carrier in relation tothe character boxes during predominately incremental, that is,character-by-character printing. Reference is also made to FIGS. a and5b which shows the grating, sensing, and counting circuits. Referring toFIG. 2, character zones or boxes designated A thru H are shown. It isassumed that the printer is in the incremental mode of printing asdetermined by appropriate depression of keybutton on the keyboard of theprinter. Initially, it is also assumed that carrier 5 and head assembly4 are located at the stop position 1000 in the printing motion line 100.It is seen that carrier 5 and head assembly 4 are actually past thecharacter location A that is the next one to be printed. Upon initiationof printing of a character as by depression of a keybutton in keyboard3, various mechanisms to be described are activated to move carrier 5and head assembly 4 to the left along line portion 100]; to a pointrepresented at 1001' prior to character box A. Thereafter, themechanisms are operable to sweep head assembly 4 and carrier 5 to theright along line 100d ultimately to a stop location 100a in readinessfor the next character. As the assemblies 4 and 5 pass through characterbox A, appropriate signals are developed to propel ink drops towarddocument 7 in order to print the character required in character box A.No printing occurs in boxes B, C, or D.

The foregoing motions and movement of structures 4 and 5 occur for theprinting of the subsequent characters in boxes B, C, D, etc., with theexception that in the case of characters D and E, continued movement ofcarrier 5 and head assembly 4 occurs. This is assumed to be due to thefact that the signals necessary for formation of the characters in thoseboxes are provided to the system during the latter portion of thecharacter box D so that the printer need not stop but may continue onand print the characters in character boxes D and E.

SYSTEM BLOCK DIAGRAM FIG. 3a is a system block diagram incorporating aprocessor, card unit, tape unit 110, or the like and having variouscontrol lines -128 interconnected with a character generator box andprinter control circuits 131. Other lines 134-141 interconnect thecharacter generator 130 and printer 131 with the head assembly 4.

In FIG. 3b the logic representing various mechanical functions hasinputs on lines 151-156 providing control for various operationalcircuits and ultimately to the printer mechanisms 161 with feedback online 163.

Referring to FIG. 4, various structures incorporated in head assembly 4are illustrated. This includes a pump 40 for directing ink from an inksupply conduit 41 on demand as a crystal 42 is energized, that is,pulsed at high frequencies. The rate of impulsing crystal 42 may be inthe range of I00 kiloHertz for example. Ink drops are emitted fromnozzle 43 and pass through a charge electrode 44 for variable chargingin accordance with the output of a charge amplifier to deflect the dropsin a column an amount representing the vertical height of the droplocation in any given character. As illustrated the letter capital Sdesignated 50 comprises a number of vertical columns 51. The printing issuch that a sequence of vertical columns, each comprising a plurality ofdrops, such as 40 in number, is propelled from nozzle 43 toward document7 for the printing of the character involved. If drops are not requiredfor printing, they are directed to a gutter 53 for passage by means of aconduit 54 back to the ink supply, customarily. A pair of deflectionplates 60 and 61 is positioned in the path of travel of the dropsleaving the charge electrode 44. A constant high potential is appliedacross plates 60 and 61 and this in cooperation with the variable chargeon the individual drops determines the amount of deflection as the dropsare directed toward document 7. Grating 8a in this instance is shown asbeing positioned horizontally rather than vertically as in FIGS. 1 and5a, but the positioning is immaterial.

Mounted on head assembly 4 for translational movement adjacent grating 8is a sensor assembly such as that shown in FIG. 5a. This comprises asupporting structure 30 incorporating a light emitting diode 32 arrangedto direct light thru grating 8 and a master grating 33 to a pair ofsolar cells 34 and 35. Grating 8 has the two portions 8a and 8b.

Grating 8 is typically of a stiff transparent base and is guided througha slot in the assembly body to maintain a reasonably constant proximityto master grating 33.

Master grating 33 is mounted to the face of the solar cells 34 and 35.Master grating 33 is arranged in such a manner that the DC. outputsignals of the two cells cancel while the AC. signals are additive. Thisis accomplished by making the grating lines of one cell l80out of phasewith respect to those of the other cell. The purpose is to reduce theeffects of light level shift which may occur from aging or voltagechange on the light emitting diode.

The two channels, as described above, produce signals that have a90phase relation skip. This is to permit up-down counting. One channel,FIG. b, comprises cell 34 coupled through amplifier 70 to And-Invert(AI) block 71, while the other channel comprises cell 35 coupled throughamplifier 73 to And-Invert 74. Outputs of Al blocks 71 and 74areprovided to up-down counter logic 75 with outputs at 76 being used todetermine print-head location.

As indicated, the individual characters are located within characterboxes comprising perhaps 40 drop cations in height and 24 drop locationsin width, that is 24 columns wide.

If it is assumed'that the printer 1 is in a line mode and the system isin a playback mode, appropriate positioning of a card, not shown,results in card unit 2 furnishing signals to the printer 1 to determinethe printing of characters. An output indicating print is provided andremains at an up level until an end of line signal is received from thecard unit.

As indicated on charge electrode 44, FIG. 4, the charge determines atwhat drop location a drop will ultimately arrive within a given columnof drops in the character box on document 7. If no drop is required,that is, it is to be directed to gutter 53, FIG. 4, then a blank signalresults in no charge on the drop and it lands in gutter 53.

TRANSPORT MECHANISMS FOR RELATIVELY MOVING CARRIER AND DOCUMENT tachedon either side of carrier 5 is a cable 201 that is illustrated aspassing around pulleys 205-208 in FIG. 6. Cable 201 is wound on a corddrum 210. Cord drum 210 is mounted on an operational shaft 21].Associated with drum 210 is a hub member 212, fixedly mounted therewithand another hub member 213. The entire assembly of elements 210, 212,and 213 being freely mounted on shaft 211. Surrounding hub member 212 isa spring element 216 forming part of a spring clutch assembly 218 whilesurrounding a portion of hub member 213 is a spring element 220 formingpart of a spring clutch assembly 221, which disengages the planetarygear system during carrier return operations to prevent gear noise.Clutch assembly 218 is involved in carrier return operations, that is,movement of carrier 5 from right to left in printer 1 while springclutch 281 is involved in a governing action when carrier 5 is movedfrom left to right in the tab or forward spacing direction.

Other primary structures associated with the transport mechanismsinclude the main spring 230, the backspace clutch assembly 231 andassociated elements arranged in a train for mechanical controldesignated 232, an index assembly 233, and a tab governor 234. i

It is assumed that carrier 5 is at the left margin location indicated byreed switch 30. If printing of a line is desired, a backspace operationis first anticipated by arm 231 and pawls 241 and 242 shown moreparticularly in FIG. 6 are disengaged from ratchet 243. This enablesdriving movement by main spring 230 through hub member 213 and cord drum210 to pull cable 201 and carrier 5 in a direction from left to right inrelation to document 7. Movement of carrier 5 continues until a lineending code is received from the data source or reed switch 32 isencountered indicating the right margin. Thereupon, a carrier returndrive is initiated, when motor 250 is coupled through hub element 212and cord drum 210 by engagement of spring element 216 of clutch assembly218 by means of a shoe 255 activated by carrier return magnet 256.Accordingly, carrier 5 is moved from right to left in the carrier returndirection until left margin switch 30 is encountered indicatingtermination of the carrier return operation. While the carrier is inoperation, main spring 230 is being wound up in preparation forescapement and tabulation movements in a succeeding line.

INCREMENTAL PRINTING If printing of information is required on acharacterby-character basis, then motion of the carrier and associatedhead assembly 4 is as shown and'discussed previously in connection withFIG. 2a. Referring to FIG. 2a, it is assumed that carrier 5 has stoppedat point 100a.

The logic is operative to initiate a backspacing operation of 0.3 inchcorresponding to three characters, assuming a 10 pitch characterincrement. The backspacing operation is initiated by energization of thebackspace clutch 231, which by means of actuator 260 moves an armassembly 261 pivotally mounted on pivot 262. The. arrangement is suchthat portion 261a moves into the figure, that is, away from the viewer,while portion 261]) moves upwardly from the surface of the figure, thatis, toward the viewer. The motion of member 261 is such that pawl 242moves ratchet 243 in a mum terclockwise direction when viewed from theright end of shaft 211. Ratchet 243 is directly associated with corddrum 210 and this effects movement of carrier 5 three character spacesback to point 100C in FIG. 2a.

Thereafter, escapement magnet 240 is energized to release ratchet 243 sothat cord drum 210 may be moved in a clockwise direction as viewed fromthe right end of shaft 211 under influence of main spring 230.

During any tabulation movement under influence of main spring 230, speedof the movement is controlled by the tab governor 234 by means of aplanetary gear assembly 270 including a ring gear 271, a planetary gear272 and a sun gear 279. The control is exerted through the springclutches 221 and 280 as well as governor 234 to insure that excessivespeeds are not encountered.

With activation of main spring 230, and rotation of cord drum 210,carrier 5 and head assembly 4 move in a left to right direction asillustrated by portion 100d in FIG. 2a with the electronics controllingthe printing of a character in character box A as required taking intoaccount the character and columnar positions of ink drops by monitoringcounter during movement of carrier 5. Escapernent magnet 240 isde-energized in time for the carrier to stop at point 100e, FIG. 2a.

Succeeding characters are printed in the incremental mode in this manneras long as required.

It is evident by inspection of FIG. 2a that with carrier 5 and headassembly 4 displaced a considerable distance to the right past anycharacter location that has just been printed, visibility is quiteimproved and the character just printed is readily inspected by theoperator of the system.

While the invention has been particularly shown and described withreference to a preferred embodiment, it will be understood by thoseskilled in the art that various changes in form and detail may bemadewithout departing from the spirit and scope of the invention.

What is claimed is:

1. In a printing apparatus having provision for successivelyincrementally printing customarily under control of an operatorindividual characters or symbols by means of a printhead inpredefined-locations on a receiving member, each of said characters orsymbols comprising components between and including a starting positionand a termination position, said apparatus being operable to print allcomponents of each individual character or symbol. during a single printcycle, each said print cycle comprising first, second and third cycleportions, a method for establishing better visibility of characters andsymbols as they are printed, comprising;

1. during the first cycle portion of each said print cycle, relativelymoving said printhead and said receiving member from a position beyondthe termination position of the character or symbol presently to beprinted in order to relatively locate said print head and said receivingmember prior to the starting position of the individual character orsymbol to be printed;

2. during the second cycle portion of each said print cycle, relativelymoving said receiving member and said printhead in a printing direction,said printhead having facilities and being operable to print componentsof said character or symbol during said relative movement;

3. during the third cycle portion of each said print cycle of eachindividual character or symbol incrementally printed, overbounding andinvariably stopping said printhead past the termination positon of saidindividual character or symbol into at least the next succeedingcharacter or symbol location so that said printhead is out of the normalsight line of an operator of said apparatus and each character andsymbol printed on said receiving member is readily visible.

2. Printing apparatus for establishing better visibility of charactersand symbols as they are printed, and having provisions for successivelyincrementally printing customarily under control of an operatorindividual characters or symbols by means of a printhead in predefinedlocations on a document, each of said characters or symbols comprisingcharacter components between and including a starting position and atermination position, said apparatus being operable to print allcomponents of each individual character or symbol during asingle symbolprint cycle, each said print cycle comprising first,

second and third cycle portions, comprising:

1. means for positioning a document for printing;

2. printhead means positioned adjacent said document for selectivelyforming, propelling, charging and deflecting marking components forselective deposition on said document;

3. first means operable during the first cycle portion of each saidprint cycle to relatively move said printheadand said receiving memberfrom a position beyond the termination position of the character orsymbol presently to be printed in order to relatively locatesaidprinthead and said receiving member prior to the starting positionof the individual character or symbol to be printed;

4. second means operable during the second cycle portion of each saidprint cycle to relatively move said document and said printhead in aprinting direction and for operating said printhead to print componentsof a said character or symbol during said relative movement;

5. third means operable during the third cycle portion of each saidprint cycle of each individual character or symbol incrementally printedto invariably stop said printhead past the termination position of saidindividual character or symbol into at least the next succeedingcharacter or symbol location so that said printhead is out of the normalsight line of an operator of said apparatus and each character andsymbol printed on said receiving member is readily visible.

3. The apparatus of claim 2 wherein said printhead means is operableduring the second cycle portions to selectively propel and deposit inkdrops on said document serving as said marking components.

1. In a printing apparatus having provision for successively incrementally printing customarily under control of an operator individual characters or symbols by means of a printhead in predefined locations on a receiving member, each of said characters or symbols comprising components between and including a starting position and a termination position, said apparatus being operable to print all components of each individual character or symbol during a single print cycle, each said print cycle comprising first, second and third cycle portions, a method for establishing better visibility of characters and symbols as they are printed, comprising:
 1. during the first cycle portion of each said print cycle, relatively moving said printhead and said receiving member from a position beyond the termination position of the character or symbol presently to be printed in order to relatively locate said print head and said receiving member prior to the starting position of the individual character or symbol to be printed;
 2. during the second cycle portion of each said print cycle, relatively moving said receiving member and said printhead in a printing direction, said printhead having facilities and being operable to print components of said character or symbol during said relative movement;
 3. during the third cycle portion of each said print cycle of each individual character or symbol incrementally printed, overbounding and invariably stopping said printhead past the termination positon of said individual character or symbol into at least the next succeeding character or symbol location so that said printhead is out of the normal sight line of an operator of said apparatus and each character and symbol printed on said receiving member is readily visible.
 2. during the second cycle portion of each said print cycle, relatively moving said receiving member and said printhead in a printing direction, said printhead having facilities and being operable to print components of said character or symbol during said relative movement;
 2. Printing apparatus for establishing better visibility of characters and symbols as they are printed, and having provisions for successively incrementally printing customarily under control of an operator individual characters or symbols by means of a printhead in predefined locations on a document, each of said characters or symbols comprising character components between and including a starting position and a termination position, said apparatus being operable to print all components of each individual character or symbol during a single symbol print cycle, each said print cycle comprising first, second and third cycle portions, comprising:
 2. printhead means positioned adjacent said document for selectively forming, propelling, charging and deflecting marking components for selective deposition on said document;
 3. first means operable during the first cycle portion of each said print cycle to relatively move said printhead and said receiving member from a position beyond the termination position of the character or symbol presently to be printed in order to relatively locate said printhead and said receiving member prior to the starting position of the individual character or symbol to be printed;
 3. during the third cycle portion of each said print cycle of each individual character or symbol incrementally printed, overbounding and invariably stopping said printhead past the termination positon of said individual character or symbol into at least the next succeeding character or symbol location so that said printhead is out of the normal sight line of an operator of said apparatus and each character and symbol printed on said receiving member is readily visible.
 3. The apparatus of claim 2 wherein said printhead means is operable during the second cycle portions to selectively propel and deposit ink drops on said document serving as said marking components.
 4. second means operable during the second cycle portion of each said print cycle to relatively move said document and said printhead in a printing direction and for operating said printhead to print components of a said character or symbol during said relative movement;
 5. third means operable during the third cycle portion of each said print cycle of each individual character or symbol incrementally printed to invariably stop said printhead past the termination position of said individual character or symbol into at least the next succeeding character or symbol location so that said printhead is out of the normal sight line of an operator of said apparatus and each character and symbol printed on said receiving member is readily visible. 